Dog Training/5 yr old lab fetch problem!

Hello.I am Rameez from India.I have a 5 yr old lab (female).she hasn't been trained all these years apart from a basic sit and hand shaking.would be fair to say she responds well to handshaking..but doesn't always seek to understand the sit command.she doesn't good with fetch the ball game too.whenever i throw..she runs..grabs it in mouth and starts chewing it.she doesn't let go the ball from her mouth.i would like you to suggest some basic commands that she needs to learn and the procedure that i should be following in order to understand what that means.plus leash walk problem.sometimes she doesn't listen and walk side by side...but sometimes she doesn't. please help.

AnswerIf the dog is already an adult then usually they are set in their ways. Dogs are either food or toy motivated. Some may also be praise motivated. But I would not say that an adult dog would have much success being trained without the assistance of a professional.

Expertise

Typically answer questions about basic obedience and search and rescue training for any types/breeds of dogs.
I DO NOT answer questions regarding any health related issues. I DO NOT PROMISE TO ANSWER QUESTIONS OTHER THAN THE AREAS I HAVE LISTED.
If you are going to ask a question I do expect to get sufficient information. I cannot make any promises that I can answer your question if it is a behavioral issue because you have to be around the animal to properly evaluate what the animal is or is not doing so do not expect a miracle through email.

Experience

Chief of local rescue squad. I have 2 trained K-9's. One is trained for live, cadaver and HRD. The second is trained for live search and in training currently for cadaver and HRD. Formerly trained Police K-9's for Patrol, protection and Narcotics.

OrganizationsAlabama Association of Rescue Squads, North American Search Dog Alliance